Respiratory syncytial virus (RSV) is a common respiratory pathogen that causes respiratory illnesses, ranging from mild symptoms to severe lower respiratory tract infections in infants and older adults. This virus is responsible for one-third of pneumonia deaths in the pediatric population; however, there are currently only a few effective vaccines. A better understanding of the RSV–host relationship at the molecular level may lead to a more effective management of RSV-related symptoms. The fractalkine (CX3CL1) receptor (CX3CR1) is a co-receptor for RSV expressed by airway epithelial cells and diverse immune cells. RSV G protein binds to the CX3CR1 receptor via a highly conserved amino acid motif (CX3C motif), which is also present in CX3CL1. The CX3CL1-CX3CR1 axis is involved in the activation and infiltration of immune cells into the infected lung. The presence of the RSV G protein alters the natural functions of the CX3CR1-CX3CL1 axis and modifies the host’s immune response, an aspects that need to be considered in the development of an efficient vaccine and specific pharmacological treatment.

Respiratory Syncytial Virus is a common respiratory pathogen known for causing respiratory illnesses, ranging from mild symptoms to severe lower respiratory tract infections in infants and the elderly. This virus is responsible for one-third of pneumonia deaths in the pediatric population, but there are currently only a few effective vaccines and pharmacological treatments. The frac-talkine (CX3CL1) receptor (CX3CR1) is a co-receptor for RSV expressed by airway epithelial cells and a diversity of immune cells. Recent research has highlighted the role of CX3CR1 in the host immune response to RSV infection, and its potential role in the development of an efficient vaccine and novel treatments.

Immunocompromised patients, including those with advanced HIV infection, hematologic malignancies treated with anti-CD20 monoclonal antibodies, or combined immunodeficiencies, are at increased risk of persistent SARS-CoV-2 infection. While long-term viral shedding has been described in these patients, the extent and nature of intra-host viral evolution during long-term infection remain insufficiently documented. In this study, we report longitudinal genomic analyses of SARS-CoV-2 from three immunocompromised individuals with persistent COVID-19: (i) a female patient with follicular lymphoma receiving bendamustine-rituximab therapy with 9 months of persistence, (ii) a male patient with advanced HIV infection following prolonged antiretroviral therapy interruption with 10 months of persistence, and (iii) a female patient with Good’s Syndrome characterized by combined humoral and cellular immune deficiency with apparently four years of persistence. Replication-competent virus was detected over extended periods. Sequential whole-genome sequencing revealed the gradual accumulation of non-synonymous mutations across multiple viral genes, consistent with ongoing viral replication and intra-host diversification in the absence of effective immune control. Although based on a limited number of cases, these findings provide descriptive evidence that persistent SARS-CoV-2 infection in immunocompromised hosts can be associated with sustained viral evolution. This work highlights the importance of continued virological monitoring in selected patients with prolonged infection and contributes to the understanding of SARS-CoV-2 dynamics in settings of impaired immunity.

The PDZ (PSD95, Dlg and ZO-1) genes encode proteins that primarily function as scaffolds of diverse signaling pathways. To date, 153 PDZ genes have been identified in the human genome, most of which have multiple protein isoforms widely studied in epithelial and neural cells. However, their expression and function in immune cells have been poorly studied. Herein, we aimed to assess the transcriptional profiles of 83 PDZ genes in human macrophages (Mɸ) and dendritic cells (DCs) and changes in their relative expression during cell PRR stimulation. Significantly distinct PDZ gene transcriptional profiles were identified under different stimulation conditions. Furthermore, a distinct PDZ gene transcriptional signature was found in Mɸ and DCs under the same phagocytic stimuli. Notably, more than 40 PDZ genes had significant changes in expression, with potentially relevant functions in antigen-presenting cells (APCs). Given that several PDZ proteins are targeted by viral products, our results support that many of these proteins might be viral targets in APCs as part of evasion mechanisms. Our results suggest a distinct requirement for PDZ scaffolds in Mɸ and DCs signaling pathways activation. More assessments on the functions of PDZ proteins in APCs and their role in immune evasion mechanisms are needed.

This is a case report of a young adult who died of COVID-19 twelve days after admission, with coronavirus nucleocapsid protein and lipofuscin found in the heart and kidney tissues, providing further evidence of the role of SARS-CoV-2 in cellular senescence.

Dengue virus (DENV), an important mosquito-borne orthoflavivirus, represents a growing global threat due to its geographic expansion and recent outbreaks worldwide. In resource-limited endemic settings, the development of affordable diagnostic assays is needed. In this study, we developed and validated a colorimetric reverse transcription loop-mediated isothermal amplification assay (RT-LAMP) for the detection of DENV type 3 (DENV-3) using 95 previously diagnosed clinical samples from Southeastern Mexico. Primers targeting the 3′ untranslated region (3′ UTR) of DENV-3 were designed, and assay conditions were standardized. The colorimetric RT-LAMP DENV-3 system achieved a preliminary limit of detection of 1 × 10³ copies per reaction, with 90.7% sensitivity and 100% specificity. The colorimetric format enabled visual readout without specialized equipment, supporting its potential applicability in point-of-care and resource-limited settings. The developed colorimetric RT-LAMP detection for DENV-3 is intended as a rapid screening/triage tool that can trigger confirmatory testing or public-health actions.